The present invention relates to combined door knob and lock for installation on bathroom, toilet and similar compartment doors where closure from inside the room is required.
In the haste to make use of bathrooms and toilets, for example, a user is frequently unaware that the facility is at that moment in use, and the user vigorously pushes and shakes the door in an attempt to gain entry. Often precious moments are lost before the user realizes he must seek another facility to his annoyance and after disturbing the prior occupant as well.
In U.S. Pat. No. 3,427,835 a locking mechanism for double swinging doors is shown in which an attempt is made at providing a signal of occupancy. Such arrangement is briefly illustrated in FIG. 1 of the attached drawings. One of the swinging doors 10 is provided with a more or less standard linear throw lock mechanism 12 having a knob 14, a latch 16, and a lever operated throw bolt 18 while the other door 20 has built into it a switch mechanism 22 having a plunger 24 extending out of the door edge in alignment with the bolt 18. When the bolt 18 is thrown into closing position it engages the plunger 22 operating the switch mechanism 22, which is connected via an electrical circuit to a lamp 26, fitted into the face of the door 20 so that the lamp 26 is lit when the plunger 22 is depressed. According to this patent, the switch mechanism 22 includes a transformer, switch and rectifier circuit requiring complex electric installations and a source of house current remote from the door itself.
A major drawback of the arrangement described in the foregoing patent is the fact that two major independent mechanical lock components are required, namely, the lock-latch device set in door 10 and switch device set in door 20, as well as the separate light indicator. In addition, the separate light indicator requires cutting of at least one hole in the face of one door. The device further requires alignment of the bolt and the plunger in each door so as to meet during normal operation of the door.
It is the object of the present invention to overcome the disadvantages and drawback of the prior art and to provide an improved door lock with light indicator.
It is a further object to provide a lock for bathroom or toilet facilities which is simple in construction and in installation and which is extremely low in cost.
Another object is to provide a lock of the aforementioned type which runs on batteries and is otherwise self-contained and does not require expensive security or electrical installation.
These objects together with other objects will be apparent from the following disclosure.